Abstract Using high-resolution scanning tunneling microscopy, we investigate the periodicity of mixed arrays of single and triple steps and the atomic structure of triple steps on three vicinal Si(111) samples with off-angles 1.5 ∘ ≤ θ ≤ 9.45 ∘ towards the [ 1 ¯ 1 ¯ 2 ] direction. The comparison between the (556) and (557) triple-step structure demonstrates that only the number of 7x7 terraces is affected by miscut. At variance with the singular Si(111) case, Ge epitaxy is strongly correlated to step morphology, resulting, at the critical coverage and small misorientation, in the nucleation of holed nanoislands from step-edge protrusions. During step-flow growth, stress-driven bunching of atomic steps (ripples) is observed on the (557) surface, indicating that this mechanism of stress relief of Si(001) vicinal surfaces works also on Si(111) surfaces.

中文翻译：

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邻位 Si (111) 表面的台阶和 Ge 外延：一项 STM 研究

摘要 使用高分辨率扫描隧道显微镜，我们研究了三个具有偏角 1.5 ∘ ≤ θ ≤ 9.45 ∘ 的邻位 Si(111) 样品的单步和三步混合阵列的周期性和三步的原子结构 [ 1¯1¯2]方向。(556) 和 (557) 三步结构之间的比较表明，只有 7x7 阶地的数量受到错切的影响。与奇异的 Si(111) 情况不同，Ge 外延与阶梯形貌密切相关，导致在临界覆盖和小错误取向下，从阶梯边缘突起形成有孔纳米岛。在阶梯流生长过程中，在（557）表面观察到应力驱动的原子阶梯（波纹）聚集，